Excavation vehicles, such as wheel loaders and dumpers often operate in dusty environments containing particles and substances which are harmful if inhaled. In order to prevent the dust from reaching the operator of the vehicle, the operator cab is provided with a dust filter through which ventilation air to the operator cab passes and is thus filtered.
For filtering out fine dust, a filter is required with a high degree of separation, which means that the filter structure will be close. Since the total amount of dust generated by the excavator is often great, the problem of the filter becoming quickly clogged will arise.
Filters used in excavators are therefore dimensioned with large surfaces to extend the time before the filter becomes clogged.
In order to prevent dust from penetrating through leaks into the cab, an overpressure is created therein. However, dust clings to the operator and accompanies him as he enters the cab. The dust which the operator brings with him will circulate inside the cab when the air in the cab is recirculated and cooled by an air conditioning system in the cab therein.